In chapter 3, Scout does not want to go to school. Things have not been going well for her. Her teacher, Miss Caroline, scolded her for reading with Atticus. And when Scout tried to be helpful about Burris Ewell and Walter Cunningham by explaining their situations, Miss Caroline was not happy. Scout was reprimanded again. In light of this, Scout did not want to go to school. In fact, she had a conversation with Atticus about this.
Atticus, as a good father, encouraged her, and made a deal with her (compromise). If Scout will go to school, they would read together every night, as they have been doing. Atticus added one more condition. Scout should not tell Miss Caroline about their reading together, lest Atticus become the target of her anger. Here is dialogue:
“No, an agreement reached by mutual concessions. It works this way,” he said. “If you’ll concede the necessity of going to school, we’ll go on reading every night just as we always have. Is it a bargain?"